B1 Cell biology Flashcards
(27 cards)
Meaning of Eukaryotic cells
Have a cell membrane,
cytoplasm and genetic material (DNA) enclosed in a nucleus.
Animal and plant cells are eukaryotic cells
Meaning of Prokaryotic cells
These are smaller than eukaryotic cells. The genetic material is not enclosed in a nucleus. The DNA is a single loop and there may be one or more rings of DNA called plasmids.
Function of Sperm
To fertilize an egg
Long tail to swim towards the egg.
Acrosome in the head containing enzymes to digest the egg cell membrane.
Large number of mitochondria in the mid section to release energy for movement.
Function of Nerve
Function to carry electric signals
Long to carry signals long distances.
Branched connections to connect to other nerve cells and form a network around the body.
Function of Muscle
Contain a large number of mitochondria to release energy from respiration for movement.
Long so that there is enough space to contract.
Function of Root Hair cell
Function is to absorb water and minerals from the soil.
Hair like projections to increase the surface area. (Note that root hair cells have no chloroplasts this is because they do not need them as they are in the soil)
Function of Xylem
Function is to carry water and minerals in plants.
Water and minerals flow from the roots towards the leaves out of the stomata only in one direction in a process called TRANSPIRATION.
Function of Pholem
Function is to carry glucose around the plant.
phloem tubes made of living tissue.
Glucose in solution moves from the leaves to growth and storage tissues through the phloem in a process called TRANSLOCATION.
What is Xylem
Water and minerals flow from the roots towards the leaves out of the stomata only in one direction in a process called Transpiration
What is Pholem
Glucose and other sugars move from the leaves to growth and storage tissues through the phloem in a process called Transloaction
What is the Magnification Equation
Magnification (M) = Size of image (I) / real size of the object (A)
Magnification Equation rearranged (calculating image size)
Size of Image (I) = Magnification (M) x Real size of object (A)
Magnification Equation (calculating real size of an object)
Real size of object (A) = Size of image(I) / Magnification(M)
What does a nucleus of a cell contain
Contains the instructions for making proteins and new cells
What are chromosomes?
Coiled strands of DNA molecules.
what is DNA
A genetic material found in the nucleus that codes for proteins.
What is Diffusion
Diffusion is the movement of particles for an area of high concentration to a area with lower concentration this does not require energy
This does not require any energy
What is Osmosis
The movement of water molecules across a partially permeable membrane from an area of a high water concentration to a region of a lower water concentration.
This does not require energy
What is Active Transport
Active transport is the movement of particles from a low concentration gradient to a high concentration gradient. Using energy - The energy is provided by respiration.
Requires energy
The larger the difference in concentration …
The faster the rate of diffusion
What are some Factors which effect rate of diffusion
Temperature,concentration gradient and the surface area of the membrane
Some adaptations of Small intestines
Internal surface is covered in millions of
folds called villi.
Villi increase the surface area.
Villi have a very good blood supply. This
maintains the concentration gradient.
Some Adaptations of the lungs
Lungs contain millions of tiny air sacs called alveoli.
Alveoli increase the surface area.
Alveoli have a very good blood supply. This maintains the concentration gradient.
Some Adaptation of fish
Gill filaments increase the surface area
Gill filaments are covered in Lammella
